Alignment means for the swash plate of a variable-capacity swash-plate type compressor

ABSTRACT

In a variable-capacity swash-plate type compressor, which can vary the outlet capacity by controlling an inclination angle of a swash plate, the swash plate is aligned by contacting a washer ( 19 ) with a tapered surface to the swash plate ( 18 ). Thus, in a case where a compression operation is not carried out or in a case where a compression operation is carried out at a small outlet capacity regarded as zero substantially, the noises, etc., which generate between the swash plate and a driving shaft ( 6 ), are inhibited.

TECHNICAL FIELD

The present invention relates to a variable-capacity swash-plate typecompressor, which is used in vehicle air-conditioning apparatuses.

BACKGROUND ART

As a conventional variable-capacity swash-plate type compressor(hereinafter, simply referred to as a compressor), a compressor has beenknown which is disclosed in Japanese Unexamined Patent Publication(KOKAI) No. 7-91,366. In this compressor, as illustrated in FIG. 11,cylinder bores 8 are formed in a cylinder block 1, inlet chambers 30 andan outlet chamber 31 are formed in a rear housing 3, and a crank chamber5 is formed in the front housing 2. These front housing 2, cylinderblock 1 and rear housing 3 are bonded with each other to constitute ahousing.

In the crank chamber 5, a driving shaft 6 is held rotatably by the fronthousing 2 and the cylinder block 1 by way of bearings 7 a, 7 b. Onto thedriving shaft 6, in-between the front housing 2, a rotor 10 is supportedsynchronously rotatably by way of a bearing 2 a, and, in-between therotor 10, a swash plate 11 is supported synchronously rotatably by wayof a pair of hinge mechanisms K, K. The respective hinge mechanisms K, Kinclude a supporting arm 17, which protrudes rearward from the rotor 10and in which a guide hole 17 a is drilled through, and a guide pin 16,which is fastened to a bracket 15, being disposed integrally andprotrudingly in front of the swash plate 11, and which has a sphereportion 16 a, being fitted idly into the guide hole 17 a reciprocatably,at the leading end. The respective hinge mechanisms K, K are disposedoppositely so as to cross over the top-dead-center position T of theswash plate 11. Between the rotor 10 and the swash plate 11, aninclination-angle reducing spring 12 is interposed, and theinclination-angle reducing spring 12 urges the swash plate 11 toward therear housing 3 in such a direction that the inclination angle reducesfrom the maximum inclination angle to the minimum inclination angle.

Further, in the swash plate 11, a through hole 20, into which thedriving shaft 6 is fitted, is drilled through. This through hole 20, asillustrated in FIG. 12, is formed so as to permit an inclination-angledisplacement of the swash plate 11 over an entire control range about aswing-shaft center Y, which is set beyond a side of the driving shaft 6,side which faces the hinge mechanisms, K, K, while interposing a shaftcenter X of the driving shaft 6 therebetween. Namely, this swash plate11, as illustrated in FIG. 11, is inhibited from further inclining inthe inclination-angle reducing direction by contacting a rear endsurface 11 b, which is formed as a concaved-shape at the trailing end ofthe through hole 20, with a circlip 13, which is engaged with thedriving shaft 6, when the inclination-angle reducing spring 12 is putinto the most extended state. On the contrary, the swash plate 11 isinhibited from further inclining in the inclination-angle enlargingdirection by contacting a front end surface 11 a, which is formed at thebottom in a slanted manner, with a rear end surface 10 a of the rotor 10when the inclination-angle reducing spring is put into the mostcontracted state.

And, pistons 9 are engaged with this swash plate 11 by way of a pair ofshoes 14, which serve as a connecting mechanism for transforming theto-and-fro swinging movement according to the inclination angle into thereciprocating movements, and the respective pistons 9 are accommodatedin the respective cylinder bores 8.

Between the cylinder block 1 and the rear housing 3, a valve plate 4,etc., are interposed. In the valve plate 4, inlet ports 32 and outletports 33 are formed to open correspondingly to the respective cylinderbores 8, and compression chambers, which are formed between the valveplate 4 and the pistons 9, are communicated with inlet chambers 30 andan outlet chamber 31 by way of the inlet ports 32 and the outlet ports33. On the respective inlet ports 32, inlet valves, not shown, aredisposed which open and close the inlet ports 32 in accordance with thereciprocate movements of the pistons 9, and, on the respective outletports 33, outlet valves, not shown, are disposed which open and closethe outlet ports 33 in accordance with the reciprocate movements of thepistons 9 while being regulated by retainers 34.

Moreover, in the cylinder block 1, an air-bleeding passage, not shown,is disposed which communicates the crank chamber 5 with the inletchambers 30, and this air-bleeding passage is opened and closed by acontrol valve, not shown.

In this compressor, when the rotor 10 and the swash plate 11 are rotatedat a predetermined angle, accompanied by the driving of the drivingshaft 6, the pistons 9 are reciprocated in the cylinder bores 8. Thus, arefrigerant gas is sucked from the inlet chambers 30 into thecompression chamber, and, after the refrigerant gas is compressed, it isdischarged into the outlet chamber 31. And, the inclination angle of theswash plate 11 is displaced by adjusting the pressure in the crankchamber 5 by the control valve, and thereby the outlet capacity of therefrigerant gas, which is discharged into the outlet chamber 31, iscontrolled.

At this moment, as illustrated in FIG. 12, when the swash plate 11 isput into the maximum inclination angle, a front lower surface 20 c andrear upper surface 20 d of the through hole 20 do not contact with aperipheral surface of the driving shaft 6. Moreover, when the swashplate 11 is put into the minimum inclination angle, a rear lower surface20 e and front upper surface 20 f of the through hole 20 do not contactwith the peripheral surface of the driving shaft 6. Namely, the throughhole 20 does not define the maximum inclination angle and the minimuminclination angle, and the clearance between the through hole 20 and thedriving shaft 6 is enlarged.

And, in this compressor, since a supporting portion 20 b in the throughhole 20 is formed as an arc shape, the peripheral surface of the drivingshaft 6 always keeps a linear contact with the supporting portion 20 b,and the supporting portion 20 b is less likely to be worn. Moreover,since the moments, which result from the compression reaction force,etc., can be received almost by the pair of hinge mechanisms K, K,regulatory surfaces 20 a, 20 a of the swash plate 11 are also lesslikely to be worn. Hence, in this compressor, the inclination angle ofthe swash plate 11 is secured reliably, and a good durability can beeffected.

However, not only in the swash-plate type compressor set forth in theaforementioned publication, but also in variable-capacity swash-platetype compressors involving wobble type ones widely, in a case where acompression operation is not carried out or in a case where acompression operation is carried out at a small outlet capacity regardedas zero substantially, it has been found out that such drawbacks takeplace in that noises and vibrations arise and colliding portions wearwhen a large vibration is applied from the exterior, drawbacks whichresult from the clearance of the inclination-angle variable swash plate.

Namely, in the variable-capacity swash-plate type compressors involvingwobble type ones widely, the swash plate is supported by providingclearances of certain extent in-between the other members, such as thedriving shaft, a sleeve, etc., so that the postures and positions,accompanied by the inclination-angle displacement, can be varied, andthereby the swash plate varies the inclination angle so that thevariable capacity is realized.

Here, in a case where the compressor carries out a compression operationat a large outlet capacity, since a compression load acts onto the swashplate from the pistons, regardless of the clearances in-between theother members, the swash plate keeps contacting with the other membersby the compression load at the predetermined positions. Hence, in thiscase, even when a large vibration is applied from the exterior, sincethe swash plate does not collide with the other members repeatedly,noises, etc., do not arise.

However, in the case where the compression operation is not carried outor in the case where the compression is carried out at a small outletcapacity regarded as zero substantially, the compression load does notact onto the swash plate, or hardly acts thereonto, if a large vibrationis applied from the exterior, since the swash plate collides with theother members repeatedly, noises, etc., arise.

In particular, in the swash-plate type compressor set forth in theaforementioned publication, since the driving shaft, which is fittedinto the through hole of the swash plate, can be the aforementionedother member, and since it is comparatively difficult to form thethrough hole with a high accuracy, this tendency is apparent.

DISCLOSURE OF THE INVENTION

The present invention has been done in view of the aforementionedconventional circumstances. In a variable-capacity swash-plate typecompressor involving wobble type ones widely, it is an object, withoutobstructing the inclination-angle displacement of the swash plateaccompanied by the variable capacity, to inhibit the drawbacks, such asthe noises, etc., in the case where the compression operation is notcarried out or in the case where the compression operation is carriedout at a small outlet capacity regarded as 0 substantially.

A variable-capacity swash-plate type compressor according to the presentinvention, which is constituted so that a crank chamber, inlet chambers,an outlet chamber and cylinder bores connected therewith are demarcatedand formed in a housing, so that pistons are accommodated reciprocatablyin the respective cylinder bores, respectively, so that a rotor,positioned in said crank chamber, is supported synchronously rotatablyonto a driving shaft, supported by the housing, and a swash plate,connected thereto by way of the rotor and a hinge mechanism, is fittedtherewith so as to make an inclination angle variable, so that aconnecting mechanism, transforming a to-and-fro swinging movement ofsaid swash plate into reciprocating movements of the respective pistons,is interposed between the swash plate and said pistons, and so that theinclination angle of said swash plate is controlled by a pressure insaid crank chamber so as to vary an outlet capacity, wherein it ischaracterized in that an aligning member, which contacts with said swashplate to align said swash plate, is interposed.

In the present compressor, since the aligning member contacts with theswash plate to align the swash plate, the clearances, which the swashplate has in-between the other members, such as the driving shaft, asleeve, etc., are absorbed while making the variations of the posturesand positions, accompanied by the inclination-angle displacement of theswash plate, possible. Hence, in the case where this compressor does notcarry out the compression operation, or in the case where it carries outthe compression operation at a small outlet capacity regarded as zerosubstantially, even when a large vibration is applied from the exterior,since the swash plate does not collide with the other membersrepeatedly, noises and vibrations do not arise, and the wears at thecolliding portions are less likely to occur.

Accordingly, the present compressor can, without obstructing theinclination-angle displacement of Lhe swash plate accompanied by thevariable capacity, inhibit the drawbacks, such as the noises, etc., inthe case where it does not carry out the compression operation or in thecase where it carries out the compression operation at a small outletcapacity regarded as 0 substantially.

As the aligning member, in a case where the driving shaft is the othermember, namely, in a case where the swash plate contacts directly withthe driving shaft, it is possible to employ a washer, which is fittedwith the driving shaft to fill up the clearance between the swash plateand the driving shaft. Alternatively, in a case where a sleeve, which isfitted with the driving shaft, is the other member, namely, in a casewhere the swash plate contacts directly with the sleeve, it is possibleto employ a washer, which fills up the clearance between the swash plateand the sleeve.

Further, it is suitable to provide the present compressor with an urgingmeans, which urges this aligning member onto a swash-plate side. This isbecause the aligning member is moved onto the swash-plate side by theurging force of the urging means so that it is likely to fill up theclearances between the swash plate and the other members.

Furthermore, it is suitable that said aligning member is disposedbetween the rotor and the swash plate, and that said urging means is aninclination-angle reducing spring, which urges the swash plate in such adirection that the inclination angle is reduced from the maximuminclination angle to the minimum inclination angle.

By utilizing the inclination-angle reducing spring, it is not needed toespecially dispose an urging means, which urges the aligning memberonly, and it is possible to realize the reduction of the product cost byreducing the number of the component parts.

Moreover, it is suitable that said aligning member is disposed on anopposite side of the rotor with respect to the swash plate, and thatsaid urging means is a return spring, which urges the swash plate insuch a direction that the inclination angle is enlarged from the minimuminclination angle to a limit angle or more.

By utilizing the return spring, it is not needed to especially disposean urging means, which urges the aligning member only, and it ispossible to realize the reduction of the product cost by reducing thenumber of the component parts. Note that, in this case, the aligningmember is disposed on an opposite side with respect to the case wherethe aforementioned inclination-angle reducing spring is utilized.

In addition, it is suitable that said aligning member includes a firstaligning member, which is disposed between the rotor and the swashplate, and a second aligning member, which is disposed on an oppositeside of the rotor with respect to the swash plate, and that said urgingmeans includes an inclination-angle reducing spring, which urges thefirst aligning member in such a direction that the inclination angle ofthe swash plate is reduced from the maximum inclination angle to theminimum inclination angle, and a return spring, which urges the secondaligning member in such a direction that the inclination angle of theswash plate is enlarged from the minimum inclination angle to a limitangle or more.

In this case, both of the aforementioned cases are combined. By aligningthe swash plate from both of the front and rear sides, withoutobstructing the inclination-angle displacement of the swash plateaccompanied by the variable capacity, it is possible to furthereffectively prevent the drawbacks, such as the noises, etc., when thecompression operation is not carried out or when the compressionoperation is carried out at a small capacity regarded as 0substantially.

It is suitable that at least one portion, which is selected from thegroup consisting of a portion with which said swash plate contacts saidaligning member and a portion with which said aligning member contactssaid swash plate, is formed as a minor-diameter tapered surface on aninner side of the swash plate.

Thus, a minor-diameter side of the tapered surface is positioned on aninner side of the swash plate, and consequently it is likely to fill upthe clearances between the swash plate and the other members.

In a case where such a tapered surface is formed on the portion withwhich the swash plate contacts the aligning member, it is possible toform it by using a cutting tool, which has a taper-processed surface atthe leading end, so as to advance the cutting tool in two directionswith respect to the swash plate, or so as to gently swing the cuttingtool or the swash plate between the two directions.

In a case where both of the portion with which the swash plate contactsthe aligning member and the portion with which the aligning membercontacts the swash plate are formed as such tapered surfaces, it ispreferred that they are formed so as to have an equal opening angle.Thus, their tapered surfaces contact superficially with each other, andaccordingly it is possible to reduce the wear between both of them.

By the way, it is not necessarily easy to process both of them so as toform the tapered surfaces having an equal opening angle. On the otherhand, even if the both of them are processed so as to form the taperedsurfaces having an equal opening angle, after a compressor is assembled,it is likely that these tapered surfaces contact in an inclined mannerbecause of the dimensions for the sliding movements, etc., and thedimensional tolerances, etc.

Hence, it is further suitable that one of the portion, with which theswash plate contacts the aligning member, and the portion, with whichthe aligning member contacts with the swash plate, is formed as aminor-diameter tapered surface on an inner side of the swash plate, andthat the other one of them is formed as a convexed curved surface.

Thus, the minor-diameter side of the tapered surface is positioned onthe inner side of the swash plate, not only it is likely to fill up theclearances between the swash plate and the other members, but also it iseasy to carry out the processing so that it is possible to realize thereduction of the production cost.

In a case where the driving shaft is the other member, that is, in acase where the swash plate contacts directly with the driving shaft, thethrough hole, into which the driving shaft is fitted, is formed throughin the swash plate like the compressor set forth in the aforementionedpublication. This through hole is formed so as to permit aninclination-angle displacement of the swash plate over an entire controlrange about a swing-shaft center, which is set beyond a side of thedriving shaft, side which faces the hinge mechanism, while interposing ashaft center therebetween. Since it is comparatively difficult to formsuch a through hole with a high accuracy, the present invention greatlyexhibits the effect especially in this case. The aligning member isfitted with the driving shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is concerned with a compressor of a First Embodiment, and is avertical cross sectional view of the major portion thereof at theminimum inclination angle.

FIG. 2 is a vertical cross sectional view of a swash plate, which isconcerned with the compressor of the First Embodiment.

FIG. 3 is a view for illustrating an inner surface of a through hole ofthe swash plate, which is concerned with the compressor of the FirstEmbodiment, only.

FIG. 4A is a cross sectional view of a washer, which is concerned withthe compressor of the First Embodiment.

FIG. 4B is a side view of the washer, which is concerned with thecompressor of the First Embodiment.

FIG. 4C is a front view of the washer, which is concerned with thecompressor of the First Embodiment.

FIG. 5 is concerned with the compressor of the First Embodiment, and isan enlarged cross sectional view of the major portion thereof at theminimum inclination angle.

FIG. 6 is concerned with the compressor of the First Embodiment, and isa vertical cross sectional view of the major portion thereof at themaximum inclination angle.

FIG. 7A is concerned with the compressor of the First Embodiment, and isan enlarged cross sectional view of the major portion thereof at theminimum inclination angle.

FIG. 7B is concerned with the compressor of the First Embodiment, and isan enlarged cross sectional view of the major portion thereof at theminimum inclination angle.

FIG. 8 is concerned with a compressor of a Second Embodiment, and is anenlarged cross sectional view of the major portion thereof at theminimum inclination angle.

FIG. 9 is concerned with a compressor of a Third Embodiment, and is avertical cross sectional view of the major portion thereof at theminimum inclination angle.

FIG. 10 is concerned with a compressor of a Fourth Embodiment, and is avertical cross sectional view of the major portion thereof at theminimum inclination angle.

FIG. 11 is a vertical cross sectional view of a conventional compressor.

FIG. 12 is a vertical cross sectional view of the major portion of aswash plate, which is concerned with the conventional compressor.

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment)

Hereinafter, the First and Second Embodiments, which materialize thepresent invention, will be described with reference to the drawings.

The compressor of the First Embodiment has a basic constitution, whichis substantially identical with the constitution illustrated in FIG. 11and FIG. 12, and differs therefrom in that it employs a swash plate 18and a washer 19, which serves as the aligning member, as illustrated inFIGS. 1-6, and in that it employs a return spring 21 as illustrated inFIG. 1.

In the swash plate 18, which this compressor employs, as illustrated inFIG. 1 and FIG. 2, a through hole 20 is drilled through similarly to thecompressor as illustrated in FIG. 11 and FIG. 12. That is, in thisthrough hole 20, as illustrated in FIG. 3, a supporting portion 20 b isformed as an arc shape about a swing-shaft center Y, and regulatorysurfaces 20 a, 20 a, which extend parallely to a shaft center X, areformed flatly in the side surfaces. The swing-shaft center Y extends ina vertical direction with respect to the shaft center X shown in FIG.11, and is set beyond a side of the driving shaft 6, the side facinghinge mechanisms K, K, while interposing the shaft center Xtherebetween. The regulatory surfaces 20 a, 20 a of such a through hole20 are, as illustrated in FIG. 5, held while providing a clearance t1 ofcertain extent between themselves and the driving shaft 6 so that it ispossible to vary the postures and positions, which are accompanied bythe inclination-angle displacement of the swash plate 18. Since thepostures and positions, which are accompanied by the inclination-angledisplacement of the swash plate 18, are made variable, and since thethrough hole 20 is formed as a complicated configuration, such aclearance t1 is large comparatively.

The through hole 20 of the swash plate 18 in this compressor differsfrom the through hole 20 of the swash plate 11 in the conventionalcompressor in terms of the following features. Namely, in thiscompressor, as illustrated in FIG. 2 and FIG. 3, in a forward (The sideof a rotor 10 is regarded as forward. Hereinafter, the notation is thesame.) rim portion of the through hole 20, tapered surfaces 20 g, 20 hare formed which are formed as a minor diameter on an inner side of theswash plate 18, and which have an opening angle of 45°, and the portionbetween both of the tapered surfaces 20 g, 20 h is made continuous by asmooth curved surface 20 i.

Both of such tapered surfaces 20 g, 20 h as well as the smooth curvedsurface 20 i are formed as hereinafter described. First, as illustratedin FIG. 2, a cutting tool B is prepared which has a tapered processedsurface having an opening angle of 45° at the leading end, after formingthe through hole 20, shown in FIG. 12, in the swash plate 18, thecutting tool B is advanced from the forward side with respect to theswash plate 18 so that the axial center of the cutting tool B goes alonga center line A1, which is disposed in a direction vertically crossing acentral plane C of the swash plate 18. On this occasion, the center lineA1 coincides with the shaft center X. Thus, as illustrated in FIG. 3, ona side of a top-dead-center position T of the swash plate 18, a taperedsurface 20 g is formed which is surrounded by signs a, b, g and h.

Then, as illustrated in FIG. 2, the swash plate 18 is swung gently abouta rotary center z, which takes a distance, being equal to the distancefrom the central plane C to the swing-shaft center Y, on the center lineA1 so that the axial center of the cutting tool B is placed on a centerline A2. Note that, without swinging the swash plate 18, it is possibleto swing the axial center of the cutting tool B. On this occasion, anangle θ between the center line A1 and the center line A2 is made into adisplacement-variable angle, which is a difference between the maximuminclination angle and the minimum inclination angle. Thus, asillustrated in FIG. 3, a smooth curved surface 20 i is formed which issurrounded by signs b, c, f and g. Moreover, on a bottom-dead-centerside of the swash plate 18, a tapered surface 20 h is formed which issurrounded by signs c, d, e and f. Note that it is possible to form thetapered surface 20 g, and so forth, by operations reverse to thisprocedure.

On these occasions, the angle θ between the center line A1 and thecenter line A2 can be broadened slightly to the opposite sides, and canbe made slightly larger than the displacement-variable angle of theswash plate 18. Specifically, it is possible to enlarge it by 1-2° onthe side of the center line A1, and to enlarge it by 1-15° on the sideof the center line A2. If such is the case, the inclination-angledisplacement is not obstructed by the contact between the swash plate 18and the washer 19, and thereby-the capacity of the compressor does notdecrease.

Note that the aforementioned rotary center Z in the processing cannotnecessarily be placed on the center line A1. It is possible to place iton a side of the swing-shaft center Y beyond the center line A1 or atthe opposite-side position. Moreover, it is possible to displace it inan axial direction.

Note that, after the cutting tool B is advanced from the forward sidewith respect to the swash plate 18 so that the axial center of thecutting tool B goes along the center line A1, it is possible totemporarily retract the cutting tool B, then to swing the swash plate 18or the cutting tool B so that the axial center of the cutting tool B issuperimposed on the center line A2, and then again to advance thecutting tool B from the forward side with respect to the swash plate 18so that the axial center of the cutting tool B goes along the centerline A2. If such is the case, the smooth curved surface 20 i, which issurrounded by signs b, c, f and g, shown in FIG. 3, is not formed, but atapered surface, which is surrounded by signs a, c, f and h, and atapered surface, which is surrounded by signs c, d, e and f, are formed,and the portion between both of the tapered surfaces is made continuousby an obtuse angle. Since the relative wear between the swash plate 18and the driving shaft 6 is less likely to occur when the portion betweenthe tapered surfaces 20 g, 20 h is made continuous by the smooth curvedsurface 20 i, it is further preferable to process the tapered surface 20g, and so forth, by the former procedure.

As additional notes, in the swash plate 18, as illustrated in FIG. 2, athrough hole 18 a is drilled through on a side of the top-dead-centerposition T for balancing, light-weighting and positioning in theprocessing, and a spot facing 18 b is dented on a side of thebottom-dead-center position for balancing and light-weighting. Moreover,in a weight 18 c, which is disposed integrally on a side of thebottom-dead-center position of the swash plate 18, as illustrated inFIG. 1, a concaved portion 18 d is dented which avoids a boss 10 bformed at the rear end of the rotor 10, and, below the concaved portion18 d, as illustrated in FIG. 6, a forward end surface 11 a is formedwhich contacts with a rear end surface 10 a of the rotor 10 so as toregulate a further inclination movement in the inclination-angleenlarging direction.

Moreover, in this compressor, the washer 19 is employed which isillustrated in FIG. 1 and FIGS. 4-6. This washer 19, as illustrated inFIG. 4, is a substantially cylinder-shaped one, which has an insidediameter D slightly larger than an outside diameter of a portion in thedriving shaft 18, portion which is positioned in the through hole 20 ofthe swash plate 18. Here, the extent that the inside diameter D islarger than the outside diameter of the portion of the driving shaft 6,as illustrated in FIG. 5, is a clearance t2, which results from adimension over which the washer 19, fitted with the driving shaft 6, isslidable in the axial direction as well as a tolerance, required inprocessing this dimension. Since the processing of the inside diameter Dis a simple cylinder-surface processing, such a clearance t2 can be madesmaller at ease than the clearance t1 between the regulatory surfaces 20a, 20 a of the through hole 20 in the aforementioned swash plate 18. Asillustrated in FIG. 4, on a backward rim portion of this washer 19 aswell, a tapered surface 19 a, which is made into a minor diameter on aninner side of the swash plate 18 and which has an opening angle of 45°,is formed. Such a washer 19, as illustrated in FIG. 1, is urged to thebackward side by an inclination-angle reducing spring 12, which isdisposed in-between the rotor 10.

Note that, in this compressor, as illustrated in FIG. 1, the returnspring 21 is employed. This return spring 21 urges the swash plate 18from the backward side in such a direction that the inclination angle ofthe swash plate 18 enlarges from the minimum inclination angle to anangle, which exceeds a returnable limit angle.

In the thus constituted compressor as well, with reference to FIG. 11,when the rotor 10 and the swash plate 18 are rotated at a specifiedangle accompanied by the driving of the driving shaft 6, the pistons 9are reciprocated in the cylinder bores 8. Thus, a refrigerant gas issuctioned into the compression chamber from the inlet chambers 30, therefrigerant gas is discharged into the outlet chamber 31 after it iscompressed. And, the angle of the swash plate 18 is displaced by thepressure adjustment in the crack chamber 5 with the control valve. Inthe meantime, as illustrated in FIG. 5, since the regulatory surfaces 20a, 20 a of the through hole 20 in the swash plate 18 are held byproviding the clearance t1 of certain extent in-between the drivingshaft 16, it is possible to vary the postures and positions, which areaccompanied by the inclination-angle displacement of the swash plate 18.And, the outlet capacity of the refrigerant gas, which is dischargedinto the outlet chamber 31, is controlled.

And, in this compressor, as illustrated in FIG. 1, in the case where thecompression operation is not carried out, or in the case where thecompression operation is carried out at a small capacity regarded aszero substantially, the compression load does not act onto the swashplate 18, or hardly acts thereonto. However, in this compressor, as acharacteristic action, the washer 19, which has the tapered surface 19 awhose minor-diameter side is positioned on an inner side of the swashplate 18, moves toward the side of the swash plate 18 by the urgingforce of the inclination-angle reducing spring 12, as illustrated inFIG. 5, the tapered surface 19 a of the washer 19 contacts with thetapered surface 20 g of the swash plate 18 with each other in asurface-to-surface manner so as to align the swash plate 18. Hence, theclearance t1, which the regulatory surfaces 20 a, 20 a of the throughhole 20 have in-between the driving shaft 6, is buried and absorbed.

Hence, in this compressor, under these circumstances, even when largevibrations are applied from a vehicle, an engine, etc., accompanied bythe travelling of the vehicle, the swash plate 18 does not colliderepeatedly with the driving shaft 6, noises and vibrations do not arise,and the wears are less likely to arise at colliding portions.

Note that, as illustrated in FIG. 6, in a case where this compressorcarries out the compression operation at a large capacity of certainextent, the swash plate 18 contacts with the driving shaft 6 by acompression load, and displaces the inclination angle under thecircumstances that the tapered surface 19 a of the washer 19 contactswith the smooth curved surface 20 i of the swash plate 18.

Hence, this compressor can prevent the drawbacks, such as the noises,etc., without obstructing the inclination-angle displacement of theswash plate 18, which is accompanied by the variable capacity, in thecase where it does not carry out the compression operation or in thecase where it carries out the compression operation at a small outletcapacity regarded as zero substantially.

In addition, since the inclination-angle reducing spring 12 urges thewasher 19, an urging member, which urges the washer 19 only, isobviated, the reduction of the product cost is realized by reducing thenumber of the component parts. The other operations and effects are thesame as those of the compressor set forth in the aforementionedpublication.

(Second Embodiment)

Like the compressor in the First Embodiment, it is not easy to processthe tapered surfaces 20 g, 20 h in the through hole 20 of the swashplate 18 and the tapered surface 19 of the washer 19 with an equalopening angle. Moreover, even when the tapered surfaces 20 g, 20 h andthe tapered surface 19 are processed with an equal opening angle, afterassembling a compressor, because of the dimension for sliding, thedimensional tolerance, etc., it is probable that these tapered surfaces20 g, 20 h contact with the tapered surface 19 inclinedly. In thesecases, as illustrated in FIGS. 7A and B, a corner P of the washer 19 islikely to contact with the tapered surfaces 20 g, 20 h, and to causewear between both of them.

Hence, in the compressor of the Second Embodiment, as illustrated inFIG. 8, a portion, at which the swash plate 18 contacts with the washer19, is formed as the tapered surface 20 g, which makes a minor diameteron an inner side of the swash plate 18, and a portion, at which thewasher 19 contacts with the swash plate 18, is formed as a convexedcurved surface 19 b. The other constitutions are the same as those ofthe First Embodiment.

When it is such a compressor, it is easy to process and accordingly torealize the reduction of the production cost. The other operations andeffects are the same as those of the First Embodiment.

(Third Embodiment)

As illustrated in FIG. 9, the aligning of the swash plate 18 can becarried out from the backward side of a through hole 20′ in the swashplate 18 by using a washer 19′. The washer 19′ has a tapered surface,which contacts with the backward side of the through hole 20′, on theforward side, and has a seating surface for a return spring 21′ on thebackward side. And, the return spring 21′ is supported by a circlip 13on the backward end side, and the washer 19′ is urged toward the forwardside by the return spring 21′. Note that the washer 19′ can be supporteddirectly with the circlip 13.

(Fourth Embodiment)

As illustrated in FIG. 10, the aligning of the swash plate 18 can becarried out by disposing the aforementioned washer 19 (a first aligningmember) and the aforementioned washer 19′ (a second aligning member) onthe both of the forward side and backward side of the swash plate 18.Note that the washer 19 is urged from the forward side to the backwardside by the inclination-angle reducing spring 12 (an urging means), andthat the washer 19′ is urged from the backward side to the forward sideby the return spring 21′ (an urging means). Since the aligning membersare thus disposed on both of the forward side and backward side, theswash plate 18 is aligned much more stably.

As having described so far, in accordance with the variable-capacityswash-plate type compressor of present invention, since it is providedwith the aligning member, which contacts with the swash plate, it ispossible, without obstructing the inclination-angle displacementaccompanied by the variable capacity, to prevent the noises, thevibrations of the swash plate, etc., in the case where the compressionoperation is not carried out or in the case where the compressionoperation is carried out at a small outlet capacity regarded as zerosubstantially.

What is claimed is:
 1. A variable-capacity swash-plate type compressor,which is constituted so that a crank chamber, inlet chambers, an outletchamber and cylinder bores connected therewith are demarcated and formedin a housing, so that pistons are accommodated reciprocatably in therespective cylinder bores, respectively, so that a rotor, positioned insaid crank chamber, is supported synchronously rotatably onto a drivingshaft, supported by the housing, and a swash plate, connected thereto byway of the rotor and a hinge mechanism, is fitted therewith so as tomake an inclination angle variable, so that a connecting mechanism,transforming a to-and-fro swinging movement of said swash plate intoreciprocating movements of the respective pistons, is interposed betweenthe swash plate and said pistons, and so that the inclination angle ofsaid swash plate is controlled by a pressure in said crank chamber so asto vary an outlet capacity, wherein it is characterized in that analigning member, which contacts with said swash plate to align saidswash plate, is interposed between said driving shaft and said swashplate; an urging means for urging said aligning member onto a side ofsaid swash plate, said urging means is an inclination-angle reducingspring, which urges the swash plate in such a direction that theinclination angle is reduced from the maximum inclination angle to theminimum inclination angle; and said aligning member is disposed betweensaid rotor and said swash plate.
 2. A variable-capacity swash-plate typecompressor, which is constituted so that a crank chamber, inletchambers, an outlet chamber and cylinder bores connected therewith aredemarcated and formed in a housing, so that pistons are accommodatedreciprocatably in the respective cylinder bores, respectively, so that arotor, positioned in said crank chamber, is supported synchronouslyrotatably onto a driving shaft, supported by the housing, and a swashplate, connected thereto by way of the rotor and a hinge mechanism, isfitted therewith so as to make an inclination angle variable, so that aconnecting mechanism, transforming a to-and-fro swinging movement ofsaid swash plate into reciprocating movements of the respective pistons,is interposed between the swash plate and said pistons, and so that theinclination angle of said swash plate and said pistons, and so that theinclination angle of said swash plate is controlled by a pressure insaid crank chamber so as to vary an outlet capacity, wherein it ischaracterized in that an aligning member, which contacts with saidswashplate to align said swash plate, is interposed between said drivingshaft and said swash plate; said aligning member includes a firstaligning member, which is disposed between said rotor and said swashplate, and a second aligning member, which is disposed on an oppositeside of the rotor with respect to said swash plate; and an urging meansfor urging said aligning member onto a side of said swash plate, saidurging means includes an inclination-angle reducing spring, which urgesthe first aligning member in such a direction that the inclination angleof the swash plate is reduced from the maximum inclination angle to theminimum inclination angle, and a return spring, which urges the secondaligning member in such a direction that the inclination angle of theswash plate is enlarged from the minimum inclination angle to a limitangle or more.
 3. The variable-capacity swash-plate type compressor setforth in either one of claim 1 or 2, wherein at least one portion, whichis selected from the group consisting of a portion with which said swashplate contacts said aligning member and a portion with which saidaligning member contacts said swash plate, is formed as a minor-diametertapered surface on an inner side of the swash plate.
 4. Thevariable-capacity swash-plate type compressor set forth in either one ofclaim 1 or 2, wherein one of a portion, with which said swash platecontacts said aligning member, and a portion, with which said aligningmember contacts said swash plate, is formed as a minor-diameter taperedsurface on an inner side of the swash plate, and the other one of themis formed as a convexed curved surface.
 5. The variable-capacityswash-plate type compressor set forth in either one of claim 1 or 2being characterized in that a through hole, into which the driving shaftis fitted, is formed through in the swash plate, the through hole isformed so as to permit an inclination-angle displacement of the swashplate over an entire control range about a swing-shaft center, which isset beyond a side of the driving shaft, side which faces the hingemechanism, while interposing a shaft center therebetween, and thealigning member is fitted with the driving shaft.